In the sector for the dispensing of water and in particular with regard to the water coolers present usually in offices or public places, there is a strongly-felt need to sanitise as much as possible the water remaining in the containers, since the prior art dispensers are particularly poor from the point of view of hygiene.
It should be noted that the storage of the water inside tanks or reservoirs may only be guaranteed for short periods of time, as the properties of the water supplying the dispensers are changeable from the moment it is stored.
For example, the stagnation associated with a low or inconsistent use and the thermal variations facilitate the proliferation of the bacterial colonies already existing in water, resulting in a degeneration of the bacteriological level after a few days, even within the framework of normal cleaning and sanitising of the parts in contact with the environment.
As is known, in effect, water is a major carrier of biological contaminants since even a water defined as “fit for drinking” has a bacteriological content (even though low) which finds the ideal environment to proliferate in the temperature range in which the dispensers referred to under this invention operate.
The colonies of bacteria, spores and toxins may only be destroyed by heating the water to a temperature of >121° C. (in 15 minutes, that is to say, after pasteurisation), which, however, is in strong contrast to the distribution of fresh water, but even with regard to hot beverages (such as, for example, coffee in pods, capsules or ground).
In effect, there are prior art teachings according to which in order to ensure an excellent quality of, in particular, coffee, but in general of all common hot beverages, the water temperature must be below boiling point (in general dispensers operate with values between 85° C. and 92° C.), since the reaching of temperatures near to 100° C. (boiling point of water at ambient pressure) would result in a bitter coffee, resulting in unpleasant flavours.
Moreover, in the case of dispensers of hot beverages, both the water arriving from the water mains and low mineral water are unsuitable for making a good coffee, resulting also in unpleasant flavours.
In effect, the water which comes from taps on the water mains, although it satisfies the purity and extremely high quality requirements, generally contains a high percentage of temporary hardness caused by the presence of carbonates.
The picture does not change even when low mineral water commonly found on the market is used, the total hardness values of which are not usually compatible with good quality beverages.
Moreover, in the case of water that flows from our taps, the high presence of chlorine causes malfunctioning and damage to the internal parts of the dispensers which limits the working life of the dispensers and at the same time results in high maintenance costs.
Alternatively, mainly with regard to water dispensers, bottles or the so-called “refill tanks” made of PET and/or similar plastic materials are often used, which are turned upside down and connected to the frame of the dispenser in such a way that the supply of the product occurs by gravity, in a necessarily “pressurised” environment.
To overcome the above-mentioned drawbacks, various kits are currently marketed, offered by the manufacturers of dispensing machines, as well as by firms in the vending sector, designed for cleaning and filtering the water, which, as well as complicating the maintenance processes for the machines and significantly increasing the operating costs, only marginally resolve the problems linked with bacterial contamination, water hardness and lime scale.
Alternatively, the prior art proposes certain solutions linked specifically to the refill tanks of water coolers, which, however, are not very practical and not free of drawbacks of various kinds.
For example, patent WO2010007744 is applied to a disposable bottle, the lateral walls of which are shaped in a concertina fashion for approximately half of their extension.
The other half, proximal to the bottom, does not have, on the other hand, the concertina and is described as being designed to collapse by inverting its extension so as to allow the (rigid) bottom to come close to the “neck” of the bottle and thus allow the empty volumes to be reduced, but not eliminated, once the maximum deformation is reached.
However, to make such a behaviour possible during deformation, the side walls cannot be made in an inexpensive fashion from polyethylene terephthalate (PET), that is, with the so-called “stretch blow moulding” process, which therefore makes the proposed solution completely out of step with the market.
Moreover, it should be noted how, even in the completely deformed configuration, the internal volume of the container remains considerable, which would in any case result in a considerable dispersion of unused water or, alternatively, the movement of unused volumes.
Moreover, since the side wall is completely flat in the end portion, the behaviour described cannot be achieved with certainty, and it certainly requires a high negative pressure action at the mouth of the container.
In light of this, although it aims to do so, the solution proposed by WO2010007744 cannot be currently made industrially at competitive costs and it is difficult to apply it to water coolers and to beverage dispensers more generally.
Other containers of a deformable type are known in the prior art, mainly linked with the need to reduce the dimensions during transport of the empty container. These containers, such as water flasks or the like, are not, however, of the disposable type, since they can be used several times.
In effect, the above-mentioned containers (such as that of patent document WO2011064523) are not made of PET and are not designed for containing liquid for a prolonged period of time.
Moreover, not arising from the need to prevent contact between air and water, these containers, although they reduce their own volume, do not minimise its internal volume, and simply reduce it sufficiently to simplify carrying in bags, handbags or backpacks.
Alternatively, there are prior art bottles shaped to favour their flattening (partial) in order to reduce the volume of the empty bottles, thus maximising the filling of waste disposal containers. These solutions, however, are limited to defining some lines of weakness along the side wall of the container, without any regard for the residual volume following the flattening, which is solely the result of the force applied by the consumer.